This invention relates to the development of novel polymeric compositions that have utility as new generation dispersant-viscosity modifiers. Overbased compositions have an excess of metal carbonate and, for that reason, are considered basic compositions. Because overbased compositions have this excess basicity, be they overbased amines, overbased acids or overbased dispersants, they can be reacted with compositions possessing acidic functionality.
U.S. Reissue 26,433 (LeSuer, Aug. 6, 1968) relates to oil soluble metal salts of substituted succinic acid acylated aliphatic polyamines and processes for their preparation. These salts are prepared by a process which comprises reacting, at a temperature within the range of from about 20xc2x0 C. to about 250xc2x0 C., (A) about two equivalents of a succinic compound selected from the class consisting of hydrocarbon-substituted succinic acids and hydrocarbon-substituted succinic anhydrides wherein the hydrocarbon substituent has at least about 50 aliphatic carbon atoms, (B) about one equivalent of a basic metal reactant selected from the class consisting of alkali metal, alkaline earth metal, lead, cadmium and zinc oxides, hydroxides, carbonates and lower alcoholates and the combination of an alkali metal hydroxide and inorganic metal salt selected from the class consisting of alkaline earth metal, lead, cadmium, zinc, nickel, and cobalt halides and nitrates, and (C) from one to about five equivalents of an amine selected from the class consisting of alkylene polyamines and hydroxy alkyl-substituted alkylene polyamines. In the usual case from about one to about two equivalents of amine is used.
U.S. Reissue 27,582 (Kahn et al., Feb. 6, 1973) relates to an overbased detergent-dispersant for an oil composition prepared by reacting a metal base, such as barium hydroxide or calcium hydroxide, with an acidic gas such as CO2, H2S, or SO2 in the presence of an amide, imide or ester derived from a high-molecular weight monocarboxylic or polycarboxylic acid of from 40 to 250 carbon atoms and from an organic nitrogen-containing compound having at least one amino group or hydroxy group, including alkylene polyamines, hydroxyalkyl amines and N-hydroxy alkyl morpholinones. Useful compositions are prepared by blending these reactions products into fuels and lubricants.
U.S. Pat. No. 3,189,543 (Criddle, Jun. 15, 1965) is directed to lubricating grease compositions, more particularly to the use of certain agents to improve the yield of calcium base greases whereby the yields of grease compositions are increased by incorporating therein an oil-soluble polyglycol polymer, which grease composition contains a calcium soap of 12-hydroxy stearic acid (or its equivalent), calcium acetate in amount of from 2 mols to 5 mols for each mol of said calcium soap of 12-hydroxy stearic acid, excess base expressed as calcium hydroxide, and calcium carbonate in amounts sufficient to impart improved consistency to said grease composition, which calcium carbonate is obtained by reacting urea with calcium hydroxide.
U.S. Pat. No. 3,271,310 LeSuer, Sep. 6, 1966) relates to new chemical compositions and to hydrocarbon compositions containing the same. More particularly, the reference relates to a novel class of chemical compositions useful as detergents and rust inhibitors. Still, more particularly, this reference relates to metal salts of hydrocarbon-substituted succinic acids. The hydrocarbon-substituted succinic compounds of the metal salt compositions are readily obtainable from the reaction of maleic anhydride or maleic acid and a high molecular weight olefin or a chlorinated hydrocarbon or other high molecular weight hydrocarbon containing an activating polar substituent, i.e., a substituent which is capable of activating the hydrocarbon molecule with respect to the reaction with maleic anhydride or the acid thereof. Said reaction involves heating equivalent portions of the maleic anhydride and hydrocarbon, for example, at a temperature within the range of from about 100xc2x0 C. to about 200xc2x0 C. The resulting product is a hydrocarbon-substituted succinic anhydride. The succinic anhydride may be hydrolyzed to the corresponding acid by treatment with water or steam. The hydrocarbon-substituted succinic acid is preferred for the purposes of this invention.
U.S. Pat. No. 3,496,105 (LeSuer, Feb. 17, 1970) relates to a process for reacting anions of acidic materials with basic metal-containing organic complexes whereby the anions are incorporated into the metal-containing complex. The anions of an inorganic acid can be reacted with a basic, carbonated Group II metal-containing complex to incorporate the anions into the reaction product. The products are useful as additives for lubricating oils and liquid hydrocarbon fuels as well as being intermediates for subsequent chemical reactions.
U.S. Pat. No. 3,714,042 (Greenough, Jan. 30, 1973) relates to the treatment of basic metal sulfonate complexes, sulfonate-carboxylate complexes and carboxylate complexes with high molecular weight carboxylic acids or derivatives thereof and the products resulting from said treatment. It relates also to the reduction of the foaming tendency of lubricating compositions containing these basic metal complexes.
U.S. Pat. No. 4,171,273 (Waldbillig et al., Oct. 16, 1979) is directed to succinate and succinimide derivatives of copolymers of ethylene and an alpha-olefin that are effective as polyfunctional additives exhibiting shear stable VI improvement, pour depressancy and dispersency when minor amounts thereof are added to lubricating oils, particularly petroleum based automotive lubricating oils. An additive concentrate, containing about 5 to 30 weight percent of these copolymer derivatives in a solvent, facilitates the introduction of the additive into a final lubricating oil blend. These polyfunctional additives may be prepared by reacting an ethylene-alphaolefin copolymer, such as ethylene-propylene copolymer with maleic anhydride in the presence of a free radical initiator. This anhydride is then reacted with a fatty alcohol to prepare the succinate ester. Any unesterified carboxylic acid or anhydride groups are then converted to the succinimide by reaction with a polyamine.
U.S. Pat. No. 4,248,718 (Vaughan, Feb. 3, 1981) relates to an overbased dispersant for lubricating oil compositions having a very low ash content as compared to conventional overbased additives, the overbased dispersant can be prepared by combining in a solvent at a temperature suitable for reaction to occur the components (a) at least one ashless nitrogen-containing compound selected from ammonia, ammonium salts, and organic compounds containing only carbon, hydrogen, and nitrogen and having at least one xe2x80x94NHxe2x80x94 group, (b) a basically reacting metallic compound, (c) at least one suspending agent for component (b), and (d) a chalcogen compound selected from carbon dioxide, carbon disulfide, carbon oxysulfide, or sulfur dioxide and mixtures thereof. To insure that the composition prepared by this reaction has a relatively low ash content, the ratio of the reactants (a), (b), (c), and (d) must be such that from about ⅓ to about xc2xe of the alkalinity value of the final product is derived from the ashless portion of these reactants.
U.S. Pat. No. 4,489,194 (Hayashi, Dec. 18, 1984) is directed to hydrocarbyl substituted carboxylic acylating agents made by reacting, optionally in the presence of chlorine or bromine, (A) one or more alpha-beta olefinically unsaturated carboxylic acid reagents containing 2 to about 20 carbon atoms, exclusive of the carboxyl-based groups with (B) one or more high molecular weight olefin polymers of more than 30 carbon atoms selected from the group consisting of
(i) interpolymers of C2-8 mono-1-olefins with C12-C30 mono-olefins,
(ii) mixtures of (a) homopolymers and/or interpolymers of C2-8 mono-1-olefins with (b) homopolymers and/or interpolymers of C12-C30 mono-olefins, and
(iii) chlorinated or brominated analogs of (i) or (ii).
U.S. Pat. No. 5,262,075 (Chung et al., Nov. 16, 1993) is directed to multifunctional viscosity index improver additives for oleaginous composition comprising reaction products of (i)(a) ethylene-alpha-olefin copolymers grafted with (i)(b) carboxylic acid material, further reacted with (ii) at least one of polyamine, polyol, about C30-C400 hydrocarbyl substituted carboxylic acid component together with polyol, or said carboxylic acid component together with polyamine, wherein the copolymer (i)(a) comprises intramolecularly heterogeneous copolymer chains containing at least one crystallizable segment of methylene units and at leant one low crystallinity ethylene-alpha-olefin copolymer segment, and wherein said copolymer has a molecular weight distribution characterized by at least one of a ratio of {overscore (M)}w/{overscore (M)}n of less than 2 and a ratio of {overscore (M)}n/{overscore (M)}w of less than 1.8.
U.S. Pat. 5,534,169 (Vinci, Jul. 9, 1996) comprises a method for reducing friction between relatively slideable components comprising applying to a slideably engaging surface of the slideable components a lubricating amount of at least one Newtonian, or non-Newtonian, metal overbased salt of a carboxylic acid wherein the metal is selected from the group consisting of lithium, calcium, sodium, barium, magnesium, and mixtures thereof, and the carboxylic acid comprises at least one linear unsaturated hydrocarbon group containing from about 8 to about 50 carbon atoms. The types of slideable components contemplated include flat-bearings, rotating bearings, lead screws and nuts, gears, hydraulic systems, and pneumatic devices.
U.S. Pat. No. 5,556,569 (Huang, Sep. 17, 1996) is directed to organic compounds having at least one hydrocarbyl group and a polar group containing at least one nitrogen, oxygen, or sulfur atom, being free from acidic hydrogen atoms and from functional groups which provide such organic compounds with acidic hydrogen atoms upon hydrolysis, can be overbased by treatment with a metallic base and a low molecular weight acid, to provide useful lubricant additives.
U.S. Pat. No. 5,562,864 (Salomon et al., Oct. 8, 1996) discloses a lubricating oil composition which comprises a major amount of an oil of lubricating viscosity and
(A) at least about 1% by weight of at least one carboxylic derivative composition produced by reacting
(A-1) at least one substituted succinic acylating agent containing at least about 50 carbon atoms in the substituent with
(A-2) from about 0.5 equivalent up to about 2 moles, per equivalent of acylating agent (A-1), of at least one amine compound characterized by the presence within its structure of at least one HN less than group; and
(B) an amount of at least one alkali metal overbased salt of a carboxylic acid or a mixture of a carboxylic acid and an organic sulfonic acid sufficient to provide at least about 0.002 equivalent of alkali metal per 100 grams of the lubricating oil composition provided that when the alkali metal salt comprises a mixture of overbased alkali metal salts of a hydrocarbyl-substituted carboxylic acid and a hydrocarbyl-substituted sulfonic acid, then the carboxylic acid comprises more than 50% of the acid equivalents of the mixture; and either
(C-1) at least one magnesium overbased salt of an acidic organic compound provided that the lubricating composition is free of calcium overbased salts of acidic organic compounds; or
(C-2) at least one calcium overbased salt of an acidic organic compound provided that the lubricating composition is free of magnesium overbased salts of acidic organic compounds.
U.S. Pat. No. 5,681,799 (Song et al., Oct. 28, 1997) is directed to an oil-soluble lubricating oil additive comprising at least one terminally unsaturated ethylene/alpha-olefin/diene interpolymer of 300 to 20,000 number average molecular weight substituted with mono- or dicarboxylic acid producing moieties (preferably dicarboxylic acid or anhydride moieties), wherein the terminal unsaturation comprises terminal ethenylidene unsaturation. The mono- and dicarboxylic acid or anhydride substituted interpolymers of this invention are useful per se as additives to lubricating oils, and can also be reacted with a nucleophilic reagent, such as amines, alcohols, amino alcohols and reactive metal compounds, to form products which are also useful lubricating oil additives, e.g., as dispersants.
Disclosed is a metal containing polymer composition comprising; a metal overbased imide or ester functionalized polymer prepared by reacting
(A) a polymer comprising
(A1) an acidic functionalized polymer or ester functionalized polymer comprising a polyolefin having attached or grafted acidic functionality or ester functionality, said polyolefin having a number average molecular weight of at least 500;
(A2) an acidic mixed ester-acid of a carboxy containing interpolymer, said interpolymer having a reduced specific viscosity of from about 0.05 to about 2 and being derived from at least two monomers, one of said monomers being a low molecular aliphatic olefin, styrene or substituted styrene wherein the substituent is a hydrocarbyl group containing from 1 up to 18 carbon atoms, and the other of said monomers being an alpha, beta-unsaturated aliphatic acid, anhydride or ester thereof, said ester being characterized by the presence within its polymeric structure of at least one of each of two pendant polar groups which are derived from the carboxy groups of said ester;
(a) a relatively high molecular weight carboxylic ester group, said carboxylic ester group having at least 8 aliphatic carbon atoms in the ester radical and
(b) a relatively low molecular weight carboxylic ester group, said carboxylic ester group having no more than 7 aliphatic carbon atoms in the ester radical; wherein the molar ratio of (a):(b) is (1-20):1 or
(A3) an ester functionalized polymer comprising a lactone comprising the reaction product of one or more hydroxyaromatic compounds which are hydrocarbyl-substituted; a carboxy-substituted carbonyl compound or a source thereof; and a carbonyl compound other than a carboxy-substituted carbonyl compound, or a source thereof;
(B) a metal overbased composition that contains reactive basic functionality comprising
(B1) a metal overbased amine wherein the reactive basic functionality is a primary or secondary amino group,
(B2) a metal overbased hydroxy substituted carboxylic acid wherein the reactive basic functionality is a hydroxy group, or
(B3) a metal overbased dispersant wherein the reactive basic functionality is a primary or secondary amino group.
The metal containing polymer composition is prepared by reacting (A) a polymer with (B) a metal overbased composition.
(A) The Polymer
Several different polymers are envisioned as comprising component (A). The first polymer, (A1) is an acidic functionalized polymer or ester functionalized polymer, the second polymer, (A2) is an acidic mixed ester-acid of a carboxy containing interpolymer and the third polymer (A3) is an ester functionalized polymer comprising a lactone.
(A1) The Acidic Functionalized Polymer or Ester Functionalized Polymer
The acidic functionalized polymer (A1) comprises a polyolefin having attached or grafted acidic functionality, said polyolefin having a number average molecular weight of at least 500. Component (A1) as an acid functionalized polymer is prepared by reacting a polyolefin with an unsaturated carboxylic acid; for example, the reaction of a polyolefin with maleic anhydride 
For the acidic functionalized polymer (A1), the acidic functionality is a carboxylic acid functionality that is derived from maleic anhydride or maleic acid.
The acidic functionalized polymer (A1) is also referred to as a substituted succinic acylating agent. The terms xe2x80x9csubstituentxe2x80x9d, xe2x80x9cacylating agentxe2x80x9d and xe2x80x9csubstituted succinic acylating agentxe2x80x9d are to be given their normal meanings. For example, a substituent is an atom or group of atoms that have replaced another atom or group in a molecule as a result of a reaction. The terms acylating agent or substituted succinic acylating agent refer to the compound per se and does not include unreacted reactants used to form the acylating agent or substituted succinic acylating agent.
The ester functionalized polymer (A1) is a polyolefin having ester functionality. The ester functionality is present due to the reaction of the polyolefin and an ester or by the esterification of the acidic functionalized polymer. Component (A1) as an ester functionalized polymer is prepared by reacting a polyolefin with an unsaturated carboxylic acid ester; for example, the reaction of a polyolefin with an ester of maleic anhydride, maleic acid or fumaric acid wherein R20 is each independently an aliphatic group containing from 1 to 18 carbon atoms. 
It is also possible to form an ester functionalized polymer (A1) from the acidic functionalized polymer. 
Another example of an ester functionalized polymer (A1) comprises a polyolefin having attached or grafted ester functionality. Component (A1) as an ester functionalized polymer can be prepared by reacting a polyolefin with an ester of the formula 
wherein each of R29 and R28 and each R25 is independently hydrogen or an aliphatic group containing from 1 to 7 carbon atoms, R27 is an alkylene group containing from 1 to 4 carbon atoms and q is 0 or 1. An especially preferred ester has R29 as hydrogen and one R25 as methyl, and the other R25 and hydrogen, R28 as methyl and q as zero to give 
which is known as glyoxylic acid methylester methylhermiacetal (GMHA). It is marketed by DSM Fine Chemicals. The reaction for the preparation of the ester functionalized polymer (A1) is shown below. 
It is necessary that unsaturation be present in the polyolefin in order for the reaction with GMHA to occur.
As used in this specification and appended claims, the terms xe2x80x9chydrocarbylxe2x80x9d or xe2x80x9chydrocarbon-basedxe2x80x9d denote a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character within the context of this invention. Such groups include the following:
(1) Hydrocarbon groups; that is, aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl or cycloalkenyl), aromatic aliphatic- and alicylic-substituted aromatic, aromatic-substituted aliphatic and alicyclic groups, and the like, as well as cyclic groups wherein the ring is completed through another portion of the molecule (that is, any two indicated substituents may together form an alicyclic group). Such groups are known to those skilled in the art. Examples include methyl, ethyl, octyl, decyl, octadecyl, cyclohexyl, phenyl, etc.
(2) Substituted hydrocarbon groups; that is, groups containing non-hydrocarbon substituents which, in the context of this invention, do not alter the predominantly hydrocarbon character of the group. Those skilled in the art will be aware of suitable substituents. Examples include halo, hydroxy, nitro, cyano, alkoxy, acyl, etc.
(3) Hetero groups; that is, groups which, while predominantly hydrocarbon in character within the context of this invention, contain atoms other than carbon in a chain or ring otherwise composed of carbon atoms. Suitable hetero atoms will be apparent to those skilled in the art and include, for example, nitrogen, oxygen, and sulfur.
In general, no more than about three substituents or hetero atoms, preferably no more than one, and most preferably no hetero atoms will be present for each 10 carbon atoms in the hydrocarbyl group.
Terms such as xe2x80x9calkyl-based groupxe2x80x9d, xe2x80x9caryl-based groupxe2x80x9d and the like have meaning analogous to the above with respect to alkyl and aryl groups and the like.
The polyolefin that is reacted with the acylating agent to form (A1) comprises an elastomeric polyolefin wherein the olefin contains up to 4 carbon atoms, an xcex1-olefin polymer wherein the olefin contains from 6 to 24 carbon atoms, a random block copolymer comprising a mono-vinyl aromatic/diene copolymer or a hydrogenated random block copolymer comprising a mono-vinyl aromatic/diene copolymer or a star polymer.
The elastomeric polyolefins are polyethylene elastomer, polypropylene elastomer, ethylene/propylene elastomer, commonly known as ethylene/propylene rubber (EPR) and ethylene/propylene/diene elastomer (EPDM).
The polyethylene and polypropylene elastomers are represented below where G is hydrogen for polyethylene and xe2x80x94CH3 for polypropylene. 
The polyolefin has a number average molecular weight ({overscore (M)}n) between 20,000 and 500,000, often from about 20,000 to about 300,000. Molecular weights of the polymeric hydrocarbon polymer are determined using well-known methods described in the literature. Examples of procedures for determining the molecular weight are gel permeation chromatography (GPC) (also known as size-exclusion chromatography) and vapor phase osmometry (VPO). These and other procedures are described in numerous publications including:
P. J. Flory, xe2x80x9cPrinciples of Polymer Chemistryxe2x80x9d, Cornell University Press (1953), Chapter VII, pp 266-316, and
xe2x80x9cMacromolecules, an Introduction to Polymer Sciencexe2x80x9d, F. A. Bovey and F. H. Winslow, Editors, Academic Press (1979), pp 296-312.
W. W. Yau, J. J. Kirkland and D. D. Bly, xe2x80x9cModem Size Exclusion Liquid Chromatographyxe2x80x9d, John Wiley and Sons, New York, 1979.
A measurement which is complementary to a polymer""s molecular weight is the melt index (ASTM D-1238). Polymers of high melt index generally have low molecular weight, and vice versa. The attached or grafted polymers of the present invention preferably have a melt index of up to 20 dg/min., more preferably 0.1 to 10 dg/min.
These publications are hereby incorporated by reference for relevant disclosures contained therein relating to the determination of molecular weight.
When the molecular weight of a polymer is greater than desired, it may be reduced by techniques known in the art. Such techniques include mechanical shearing of the polymer employing masticators, ball mills, roll mills, extruders and the like. Oxidative or thermal shearing or degrading techniques are also useful and are known. Details of numerous procedures for shearing polymers are given in U.S. Pat. No. 5,348,673 which is hereby incorporated herein by reference for relevant disclosures in this regard.
The ethylene/propylene elastomer is made by mixing the same or different mole amounts of ethylene and propylene and then copolymerizing the mixture to form a copolymer as below: 
The ethylene/propylene elastomer may contain minor amounts, i.e., up to about 10% based on the molar amounts of monomeric ethylene and propylene units in the elastomer, of polymerized units derived from other monomers. Examples of such other monomers include polymerizable monoolefins having at least 4 carbon atoms such as 1-butene, 1-pentene, 2-butene, 3-hexane, 4-methyl-1-pentene, 1-decene, 1-nonene, 2-methyl-propene and 1-dodecene. They include also polyenes, i.e., those having 2 or more olefinic linkages, such as conjugated polyenes, for example, butadiene, isoprene, piperylene, 1,3-hexadiene, 1,3-octadiene, etc. There may further be non-conjugated polymers such as 3,3-dimethyl-1, 4-hexadiene, dicyclopentadiene, etc. For the most part, such other monomers preferably contain from 4 to about 10 carbon atoms although they may contain as many as 25 carbon atoms.
The ethylene/propylene elastomer is derived from about 2 to 98% weight ethylene with the remainder being propylene. Elastomers containing from about 20% to about 70% (molar) of polymerized propylene, from about 30% to about 80% of polymerized ethylene, and up to about 10% of another polymerized olefin are also useful.
The ethylene/propylene/diene elastomer has numerous sources. For example, Ortholeum(copyright) 2052 (a product marketed by DuPont Company), is a terpolymer having an ethylene:propylene weight ratio of about 57:43 and containing 4-5 weight % of groups derived from 1,4-hexadiene monomer. Other commercially available olefin/diene copolymers including ethylene-propylene copolymers with ethylidene norbornene, with dicyclopentadiene, with vinyl norbornene, with 4-vinyl cyclohexene, and numerous other such materials are readily available. Olefin-diene copolymers and methods for their preparations are described in numerous patents, including the following U.S. Pat. Nos. 3,291,780; 3,300,459; 3,598,738; 4,026,809; 4,032,700; 4,156,061; 3,320,019; 4,357,250.
The xcex1-olefin polymers obtained herein are typically liquids having a viscosity of less than 150,000 cps at xe2x88x9240xc2x0 C. The xcex1-olefin monomers used to prepare the xcex1-olefin polymers are described by the formula R12CHxe2x95x90CH2. The group R12 is a hydrocarbyl residue containing from 6 to 16 carbon atoms. In particular, the xcex1-olefin which contains 6 carbon atoms is preferably the simplest hydrocarbon species, e.g., 1-hexene. Thus, the particularly desirable xcex1-olefin monomers do not contain a second reactive vinyl group, e.g., 1,4-hexadiene. It is further desirable that any additional unsaturation within the xcex1-olefin monomer should also be minimized or eliminated.
Thus overall, the preferred species in the present invention is an (xcex2-olefin which contains a simple vinyl group (olefin) at the terminus of the molecule (mono-alpha-olefin). Specific examples of a-olefins which may be utilized herein are 1-hexene, 1-heptane, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene and 1-octadecene. Also useful are small amounts of non-vinyl olefins. Thus, materials such as 2-methyl-1-pentene CH3CH2CH2C(CH3)xe2x95x90CH2 are useful herein. Typically non-vinyl olefins should not be present at more than about 10%, preferably 5% by weight of the total olefin charge. Preferably, the polyolefin will contain no non-vinyl olefins.
Branching in the olefin monomer away from the 1 and 2 carbon positions is also within the scope of the invention. While branched xcex1-olefins are not desired, they may be included at less than 10%, preferably less than 5% by weight. Branched xcex1-olefins include 3-methyl-1-pentene.
Particularly useful are mixtures of xcex1-olefins. In particular, mixtures of the normal xcex1-olefins: octene and dodecene; heptene and nonene; hexene and decene; and octene and tetradecene are useful when employed herein. Ternary mixtures such as the normal octene, dodecene and hexadecene may be used. A further desirable ternary mixture of xcex1-olefins includes a mixture of the normal octene, dodecene and tetradecene.
Where binary mixtures of two cc-olefins are utilized, they are typically present at from 5% to 95%, preferably 10% to 90% by weight of each of the xcex1-olefins. Where ternary mixtures are employed, each of the xcex1-olefins will be utilized at from about 5% to about 90%, preferably about 10% to about 70% of each of the monomers.
The catalysts employed are a first catalyst system comprising a secondary tertiary organo halide and a second system employing a Lewis acid catalyst.
The tertiary organo halides are of the formula R13R14R15CX wherein X is halogen and R13, R14, and R15 are hydrocarbyl groups. The value of X as halogen may be any of the typically employed halogen atoms, e.g., fluorine, chlorine, bromine or iodine. Preferably X is chlorine or bromine and most preferably is chlorine.
The R13 through R15 may be the same or different and preferably are the same and most preferably are alkyl. It is preferred that the total number of carbon atoms in the tertiary alkyl halide be from 4 to 12 carbon atoms. Preferred tertiary organo halides are t-butyl chloride and t-amyl chloride and a preferred secondary organo halide is sec-butyl chloride.
The Lewis acid catalyst is any material which catalyzes the desired reaction to obtain the xcex1-olefin polymer and which is further described as a molecule or ion that can combine with another molecule or ion by forming a covalent bond with two elections from the second molecule or ion. Specific examples of Lewis acid catalysts useful in preparing the xcex1-olefin polymers are boron trifluoride, aluminum halides such as aluminum chloride, aluminum monochlorodibromine, aluminum bromide and aluminum monobromodichloride.
An aprotic solvent is typically utilized in preparing the xcex1-olefin polymers. The solvent is a normally liquid material at 20xc2x0 C. The solvent is also preferably a halogenated hydrocarbon. Typically, the solvent will be methylene chloride. Other solvents comprise monobromomonochloromethane; methylene bromide, 1,2-dichloroethane; 1,1-dibromocyclopropane; 1,1-dichlorocyclopropane; cis-1,2-dichlorocyclopropane; trans-1,2-dichlorocyclopropane; cis-1,2-dibromocyclopropane and trans-1,2-dibromocyclopropane.
The solvents utilized herein are preferably general dichloro compounds such as ethylene dichloride or methylene chloride.
A further feature is to conduct the polymerization reactions in the presence of an activating amount of a protic compound. Hydrocarbon solvents can also be used as protic compounds, as well as nitro-methane and halogenated aromatics such as dichlorobenzene. Typically, the protic compound is water. An activating amount of the protic compound is typically less than 1%, preferably 0.0001% to 0.1% by weight of the catalyst system. The term xe2x80x9cactivating amountxe2x80x9d means that amount which promotes the overall polymerization reaction and is not such an amount as to substantially decrease the polymerization reaction or to inactivate the catalyst system.
Typically, the number average molecular weight of the xcex1-olefin polymers obtained will be from 2,000 to 100,000 (Mn).
The random block copolymer comprising the mono-vinyl aromatic/diene copolymer comprises the simultaneous copolymerization of two monomers. One monomer is a conjugated diene and the other monomer is a mono-vinyl aromatic. The random block copolymer formed will contain double bonds and may then be hydrogenated to remove some or substantially all of the unsaturation. In the formation of the ester functionalized polymer (A1), it is necessary that unsaturation be present in the polyolefin such that a reaction with GMHA can occur.
Examples of vinyl substituted aromatics include styrene, alpha-methylstyrene, ortho-methylstyrene, meta-methylstyrene, para-methylstyrene, para-tertiary-butylstyrene, with styrene being preferred. Examples of conjugated dienes include piperylene, 2,3-dimethyl-1,3-butadiene, chloroprene, isoprene and 1,3-butadiene with isoprene and 1,3-butadiene being particularly preferred. Mixtures of such conjugated dienes are useful.
The vinyl substituted aromatic monomer content of these random block copolymers is in the range of from about 20 percent to about 70 percent by weight and preferably from about 40 percent to about 60 percent by weight. Thus, the aliphatic conjugated diene monomer content of these copolymers is in the range of from about 30 percent to about 80 percent by weight and preferably from about 40 percent to about 60 percent by weight.
What follows is a discussion on the different types of random block copolymers.
I. Random Copolymers: Those in which the comonomers are randomly, or nearly randomly, arranged in the polymer chain, with no significant degree of blocking homopolymer segments of either monomer. The general polymer structure of a random copolymer can be represented by:
-S-D-D-S-D-S-S-D-S-D-S-S-D-S-S-D-D-S-D-D-S-D-
wherein S denotes a vinyl aromatic monomer such as styrene, and D denotes a conjugated diene monomer such as 1,3-butadiene or isoprene. Such random copolymers, may easily be made by free radical copolymerization.
While the diene monomer introduces an olefinic unsaturation of some sort, either in the main backbone of the polymer, or pendant on it, it is to be understood that the olefinic sites may be substantially removed by hydrogenation.
II. Regular Linear Block Copolymers: Those in which a small number of relatively long chains of homopolymer of one type of monomer are alternately jointed to a small number of relatively long chains of homopolymer of another type of monomer. Normal, or regular, block copolymers usually have from 1 to about 3, preferably only from 1 to 2 relatively large homopolymer blocks of each monomer. Thus, a linear regular diblock copolymer of styrene or other vinyl aromatic monomer S and conjugated diene D would have a general structure represented by a large block of homopolymer S attached to a large block of homopolymer D:
SSSSSSSSSSSSS--DDDDDDDDDDDDDDDDDDDD
The blocks of monomer S and monomer D are not necessarily of the same size or molecular weight. As before, it is understood that the initial olefinic unsaturation introduced into the copolymer by diene monomer D has been substantially removed by hydrogenation. Linear diblock copolymers comprising hydrogenated poly-(styrene-b-isoprene) are sold under the trade names xe2x80x9cShellvis 40, 50 and 90xe2x80x9d by Shell Chemical Company.
In like manner, regular triblock copolymers are understood as having three relatively large major blocks, or segments of homopolymer composed of either two monomers; i.e., as in:
SSSSSSSSSSSS-DDDDDDDDDDDD-SSSSSSSSSSSSSS
and,
DDDDDDDDDDD-SSSSSSSSSSSSSSS-DDDDDDDDDDDDD
A third monomer A may also be incorporated in these linear, regular block copolymers. In this instance, several configurations are possible, depending on how the homopolymer segments are incorporated with respect to each other. For example, a linear triblock copolymer of monomers S, D and A could be represented by several different configurations:
DDDDDDDDDDD-AAAAAAAAAAAAAAA-SSSSSSSSSSSSSSS,
DDDDDDDDDDD-SSSSSSSSSSSSSSS-AAAAAAAAAAAAAAA,
or,
AAAAAAAAAAAA-DDDDDDDDDDDDDD-SSSSSSSSSSSSSSS.
III. Linear Random Block Copolymers: Those in which a relatively large number of relatively short segments of homopolymer of one type of monomer alternate with a relatively large number of short segments of homopolymer of another monomer type.
Random block polymers of this invention may be linear, or they may be partially, or highly branched. The relative arrangement of homopolymer segments in a linear random block polymer, which is the most preferred block polymer of this invention, may be represented by:
-DDDD-AAAAA-DDD-AA-DDDDD-AAA-DD-AAAAAA-DDD-
wherein D represents a conjugated diene monomer, and A represents a vinyl aromatic monomer. The arrangement of the individual homopolymer segments of each type of monomer in a linear random block polymer is alternating.
IV. Linear Tapered Random Block Copolymers:
A special type of configuration in linear random block copolymers is the linear tapered random block structure. In this arrangement, a major portion of the polymer backbone is of the random block type, with larger blocks of one type of homopolymer situated at one end of the molecule. The synthesis of this type of polymer is usually carried out by preparing a linear random block copolymer, then adding more of one of the monomer types near the end of the polymerization, so that the additional polymer forms a series of ever larger homopolymer blocks at the end of the growing linear polymer chain. The vinyl substituted aromatic monomer is generally chosen to provide the larger, tapered homopolymer blocks, although other types of monomers may be used for this purpose.
SSSSSSSSSSSSSSSSSS-DD-SSSSS-DDD-SSS-DDD-SS-DDDD
Linear tapered random block copolymers may have significantly different solubilities in diluents normally used in lubricant formulations, as well as superior thickening power at high temperature, better high temperature viscosity under conditions of high shear, and improved low temperature viscometrics, compared to simple random block copolymers of similar molecular weight, made from the same monomers.
In general, it is preferred that these block copolymers, for reasons of oxidative stability, contain no more than about 5 percent and preferably no more than about 0.5 percent residual olefinic unsaturation on the basis of the total number of carbon-to-carbon covalent linkages within the average molecule. Such unsaturation can be measured by a number of means well known to those of skill in the art, such as infrared, NMR, etc. Most preferably, these copolymers contain no discernible unsaturation as determined by the aforementioned analytical techniques.
The random block copolymers typically have a number average molecular weight in the range of about 5,000 to about 1,000,000; preferably about 30,000 to about 300,000. The weight average molecular weight for these copolymers is generally in the range of about 50,000 to about 500,000; preferably about 30,000 to about 300,000.
Hydrogenation of the unsaturated block polymers obtained initially as polymerization products produces polymers that are more oxidatively and thermally stable. Reduction is typically carried out at part of the polymerization process, using finely divided, or supported, nickel catalyst. Other transition metals may also be used to effect transformation. Hydrogenation is normally carried out to the extent of reducing approximately 94-96% of the olefinic unsaturation in the initial polymer. This means that the manner in which the diene monomer incorporates becomes an important parameter affecting the final physical and solution properties of the hydrogenated polymers at ambient and low temperatures. The figure below shows diene incorporated both in a 1,4-cis and 1,2-manner. Hydrogenation of a 1,4-cis configuration produces linear polyethylene segments in the polymer, reducing solubility in general, and introducing highly crystalline sites that tend to associate at low temperatures, and introduce potentially undesirable melt-associated thermal transitions. 
In contrast, hydrogenation of the olefin introduced by 1,2-polymerization of the diene results in a pendant alkyl group that enhances solubility, decreases crystallinity in the diene segments, and substantially reduces the tendency toward association. The ability to control the balance of 1,4- and 1,2-modes of diene monomer incorporation, in order to optimize overall properties of the hydrogenated block polymer, for use as a viscosity modifier in lubricating oil compositions.
Isoprene incorporates into block polymers in a similar manner to that of 1,3-butadiene, i.e., either by 1,4-cis or 3,4-polymerization. As with 1,3-butadiene, predominantly cis-1,4-incorporation is usual in non-polar paraffinic solvents, but promoters, such as tetrahydrofuran, favor 3,4-polymerization. Again, a balance of properties may be achieved by using small amounts of electron-rich promoters to speed initiation and polymerization, and to influence the nature and properties of the final, hydrogenated polymer. With isoprene, there will be no possibility of formation of crystalline polyethylene segments on the hydrogenation, because there will always be aliphatic substituents in the polyisoprene blocks. 
It can be seen, then that the physical and solution properties of block copolymers are dependent on both the monomers used, and the method of preparation. The morphological characteristics of polymer solutions are similarly dependent on polymer microstructure. Morphology refers to the actual conformation of polymers under a defined set of conditions, and is dependent on structure, polymer concentration, temperature, and additional influences of solvents and other agents. Many types of block polymers show a good deal of intermolecular associative behavior, wherein blocks, or segments, of like homopolymer may agglomerate. In this sense, the block polymers demonstrate a kind of surface-active nature,wherein they form micelles, similar to those formed by classical surfactants. Supporting this property are studies which have shown that block polymers have the ability to stabilize colloidal dispersions.
In general, polystyrene-block-polyisoprene hydrogenated diblock copolymers have two relatively large segments associated to a much greater degree than do random block polymers of similar composition and molecular weight. Typically, the diblock copolymer concentrate can contain no more than about 6% by weight, and the random block copolymer no more than about 8% to be pourable at 100xc2x0 C.
In general, it is preferred that these block copolymers, for reasons of oxidative stability, contain no more than about 5 percent and preferably no more than about 0.5 percent residual olefinic unsaturation on the basis of the total number of carbon-to-carbon covalent linkages within the average molecule. Such unsaturation can be measured by a number of means well known to those of skill in the art, such as infrared, NMR, etc. Most preferably, these copolymers contain no discernible unsaturation as determined by the aforementioned analytical techniques.
Examples of commercially available random block copolymers include the various Glissoviscal block copolymers manufactured by BASF. Two especially preferred copolymers are Glissoviscal(copyright) SGH and Glissoviscal(copyright) CE-5260.
Star polymers are polymers comprising a nucleus and polymeric arms. Common nuclei include polyalkenyl compounds, usually compounds having at least two non-conjugated alkenyl groups, usually groups attached to electron withdrawing groups, e.g., aromatic nuclei. The polymeric arms are often homopolymers and copolymers of conjugated dienes and monoalkenyl arenes and mixtures thereof.
The polymers thus comprise a poly(polyalkenyl coupling agent) nucleus with polymeric arms extending outward therefrom. The star polymers are usually hydrogenated such that at least 80% of the covalent carbon-carbon bonds are saturated, more often at least 90% and even more preferably, at least 95% are saturated.
The polyvinyl compounds making up the nucleus are illustrated by polyalkenyl arenes, e.g., divinyl benzene and poly vinyl aliphatic compounds.
Dienes making up the polymeric arms are illustrated by butadiene, isoprene and the like. Monoalkenyl compounds include, for example, styrene and alkylated derivatives thereof.
Star polymers are well known in the art. Such material and methods for preparing same are described in numerous publications and patents, including the following United States patents which are hereby incorporated herein by reference for relevant disclosures contained therein: U.S. Pat. Nos. 4,116,917; 4,141,847; 4,346,193; 4,358,565; and 4,409,120.
Star polymers are commercially available, for example, as Shellvis 200 sold by Shell Chemical Co.
In order to form (A1), the polyolefin is reacted with the unsaturated carboxylic acid. Typically, the unsaturated carboxylic acids are acrylic acid, fumaric acid, maleic anhydride and the like. Maleic anhydride is the preferred unsaturated carboxylic acid. Generally, the reaction involves heating the polyolefin and the unsaturated carboxylic acid at a temperature of about 120xc2x0 C. to about 200xc2x0 C. in the presence of a free radical initiator. Mixtures of these polyolefins as well as mixtures of unsaturated mono- and poly-carboxylic acids can also be used. Alternatively, when an unsaturated polyolefin is present, the reaction to form (A1) may be conducted thermally (up to 200xc2x0 C.) or in the presence of chlorine gas.
In the reaction of the polyolefin with the unsaturated carboxylic acid, the carboxylic acid is present within the acid functionalized polymer (A1) at from 0.001 to about 5%.
In another alternative, unsaturated polyolefins can be reacted with glyoxylic reactants such as GMHA or glyoxylic acid.
The following examples illustrate the preparation of (A1). Unless otherwise indicated, in these examples and in other parts of this specification, as well as in the appended claims, all parts and percentages are by weight.